The present invention relates to embodiments of an apparatus and method for forming a cotter pin. Cotter pins are generally metallic fasteners with two tines that are bent during installation. The cotter pin holds two different components together while allowing the two components to move or rotate with respect to each other. In one example, a first of the two components is inserted through a second component and the cotter pin is inserted into an aperture in the first component. The two tines are bent such that the cotter pin cannot be removed from the first component. An example of a commercial vehicle application for cotter pins includes inserting a cotter pin through a clevis pin and bending the cotter pin tines to connect a yoke to a slack adjuster via the clevis pin.
Several methods exist for bending the tines of a cotter pin. One common method is a manual method where the operator uses pliers to first grab one of the tines of the cotter pin and bend the pin outward away from the other tine. Then the operator grabs the second tine of the cotter pin and bends the second tine in the opposite direction. Manual bending of the tines requires a twisting motion of the operator's wrist, which may cause ergonomic issues over long periods of repetitive motion. There is no automatic check in the process to confirm that the operator actually bent both tines. The bend may not have been complete enough to hold the cotter pin in the first component and the cotter pin may fall out of the first component.
Another method to bend cotter pins is the use of automatic tools. Automatic tools are typically rotational tools that grab one longer tine of the cotter pin and bend the longer tine first. Then the tool rotates again to grab the second shorter tine of the cotter pin to bend it in an opposite direction. These machines are generally large and are designed for applications where the cotter pin is easily accessible. The automatic machines require special types of cotter pins having one tine longer than the other.